Waymo Publishes Safety Data On Self-Driving Cars

Google sister company Waymo has disclosed crash data on its self-driving cars for the first time, saying its vehicles have been involved in 18 minor accidents since the beginning of 2019.

The company, which was spun out of Google in 2016 and is now owned by Google parent Alphabet, opened its driverless taxi service, which operates in a limited area of the Phoenix suburbs, to the public last month.

Waymo said it was releasing the data to improve transparency and to build public trust, as well as to open a dialogue around establishing industry-wide safety standards for self-driving cars.

The company operates several hundred vehicles in a 100-square-mile service area in the Phoenix suburbs, with fully driverless cars restricted to an area about half that size.  Waymo hasn’t disclosed how many of its vehicles operate without safety drivers.

Rear-end collisions

The company said its vehicles had one minor incident for about every 339,000 miles travelled, for a total of 18 incidents, with another 29 avoided during the reporting period of January 2019 through September 2020.

None of the 47 incidents, including those that were avoided and were only recorded in the form of a simulation, involved or would have involved serious injuries, Waymo said.

Waymo’s cars were rear-ended 11 times, with Waymo saying the figure was not above the average for human-driven vehicles in the Phoenix area.

The only case in which a Waymo car rear-ended another vehicle occurred in simulation, and was avoided when the Waymo car’s human driver took control.

In that case, a car swerved in front of the Waymo vehicle and braked hard in spite of the lack of an obstruction ahead, evidently in an effort to harass the Waymo car, the company said.  The impact, if it had occurred, would have taken place at 1 mph, according to Waymo.

The company highlighted eight incidents as “severe or potentially severe”, with five of these occurring only in simulation after having been avoided through the intervention of a human driver.

Human error

In all eight cases, other drivers’ errors contributed to the collisions, Waymo said.

Only one collision took place at an intersection, when a vehicle ran a red light at 36 mph and ran into a Waymo car that was travelling through the intersection at 38 mph.

In another case, a vehicle suddenly crossed in front of a Waymo car that was travelling at 41 mph, upon which the car’s safety driver took control and braked to avoid a collision.  A simulation found that Waymo’s self-driving software wouldn’t have braked in time to avoid the crash, slowing the card to only 29 mph.

Waymo said in its study that the safety hazard posed by human drivers sharing the road with autonomous vehicles (AVs) is likely to remain a “challenge” for the forseeable future.

“The frequency of challenging events that were induced by incautious behaviours of other drivers serves as a clear reminder of the challenges in collision avoidance so long as AVs share roadways with human drivers,” the company said.